The drug compound having the adopted name “decitabine” has chemical names: 4-amino-1-(2-deoxy-β-D-erythropentofuranosyI)-1,3,5-triazin-2-(1H)-one; or 5-aza-2′-deoxy cytidine; and is structurally represented by formula (I).

Decitabine, a pyrimidine nucleoside analog of cytidine, is used for treating patients with myelodysplastic syndromes (MDS) including previously treated and untreated, de novo and secondary MDS of all French-American-British subtypes (refractory anemia, refractory anemia with ringed sideroblasts, refractory anemia with excess blasts, refractory anemia with excess blasts in transformation, and chronic myelomonocytic leukemia) and intermediate-1, intermediate-2, and high-risk International Prognostic Scoring System groups.
Decitabine is the active ingredient in the commercially marketed product DACOGEN®, in the form of a sterile lyophilized powder for injection.
U.S. Patent Application Publication No. 2006/0014949 discloses pharmaceutical compositions and methods for treatment of neoplastic conditions using polymorphs of decitabine. This publication also discloses methods for manufacturing and administering such pharmaceutical compositions. This publication also discloses that two anomeric forms of decitabine can be distinguished, wherein the β-anomer is the active form of decitabine. The publication mentions various modes of decomposition of decitabine in aqueous solution, namely: (a) conversion of the active β-anomer to the inactive α-anomer; (b) ring cleavage of the aza-pyrimidine ring to form N-(formylamidino)-N′-beta-D-2′-deoxy-(ribofuranosy)-urea; and (c) subsequent forming of guanidine compounds.
U.S. Patent Application Publication No. 2010/0087637 discloses a method for producing a β-enriched protected decitabine comprising: a) coupling a protected 2-deoxy-ribofuranose with a protected 5-azacytosine in the presence of a catalyst to form a reaction mixture comprising a protected decitabine; and b) quenching the reaction mixture of step a) with a base. The publication discloses that the ratio of the undesired α-anomer to the desired β-anomer of the protected decitabine precursor is dynamic both under the reaction conditions of the anomers formed and also during the work-up process, specifically due to epimerisation of the carbohydrate C1 chiral center formed in the coupling reaction. The undesired α-anomer was found to become enriched following its formation by this epimerisation. The α-anomer was found to be the thermodynamically favored isomer. This publication discloses a method to avoid the undesired enrichment of the α-anomer, to maintain the relative and absolute amounts of the β-anomer initially formed in the coupling reaction.
U.S. Patent Application Publication No. 2012/0046457 discloses processes for the preparation and purification of decitabine and processes for the preparation of a crystalline form of decitabine. The publication discloses a process for purifying decitabine comprising first providing a solution of decitabine in dimethylsulphoxide and then crystallizing a solid from the solution of decitabine and dimethylsulphoxide. Crystallizing can be achieved by combining an anti-solvent with the solution. Such anti-solvents include an alcohol, an ester, or any mixture thereof, and the anti-solvent in one embodiment is a mixture of methanol and ethyl acetate.